During the past year, the major methodological and basic descriptive data have been summarized and submitted for publication. The methodological papers described the NCS-A background and measures (Merikangas et al 2009), study design and sampling (Kessler et al, 2009), field procedures (Kessler et al, 2009) and concordance of DSM-IV diagnosis from CIDI interview with clinical reassessments (Kessler et al, 2009). In addition, substantial work by our Harvard collaborators on the validity of individual diagnostic entities in the NCS-A diagnostic interview has been completed, and several manuscripts describing this work are in various stages of publication (Green et al, a, b, c) The primary effort of the NIMH team during the past year has been to review the diagnostic algorithms that were initially developed at Harvard University in order to , to define severity of cases using higher thresholds for impairment, to develop definitions of subthreshold disorders, and to create variables for service utilization. We have also processed the diagnostic data, developed codebooks and began constructing secondary variables for analysis. The NIMH team has also made substantial progress on defining the priorities for descriptive analyses of several specific disorders including mood, anxiety, eating, migraine, and substance abuse. Work groups including both intramural and extramural collaborators have been established in each of these areas. These efforts have yielded several manuscripts covering a wide range of adolescent mental health topics, including: (1) the prevalence of mental disorders in the U.S. adolescent population, (2) service patterns for mental disorders among these youth, and (3) comprehensive, disorder and topic-specific papers that examine mania, major depression, anxiety, and eating disorders, as well as migraine, suicide, tobacco use, and child neglect. The first publication of lifetime prevalence rates the full range of DSM-IV mental disorders in U.S. adolescents and their individual and familial correlates is now in press. The overall prevalence of disorders with severe impairment and/or distress was 22.2%;(11.2% with mood disorders;8.3% with anxiety disorders;9.6% behavior disorders). The median age of onset for disorder classes was earliest for anxiety (6 years), followed by 11 years for behavior, 13 years for mood, and 15 years for substance use disorders. We have also completed the analyses of lifetime service patterns for mental disorders in U.S. adolescents in collaboration with Mark Olfson, Ph.D. of Columbia University. Service rates were highest among those with attention-deficit/hyperactivity disorder (68.0%) and behavior disorders (45.4%), but less than one in five affected adolescents received services for their anxiety, eating or substance use disorders. Hispanic and non-Hispanic black adolescents were less likely than their white counterparts to receive services for mood and anxiety disorders, even when such disorders were associated with severe impairment. The manuscript has been submitted for publication. We have recently completed a parallel analysis for patterns of 12-month service utilization. 45% youth with 12 month disorders received services from any source and are in the process of preparing a manuscript reporting these findings in collaboration with our extramural collaborators. Other analyses that have been conducted and submitted for publication include: (1) A latent class analysis (LCA) on a subsample 2,539 adolescents with lifetime anxiety disorders to identify empirical subgroups and to examine their developmental and clinical correlates. A seven class solution provided the best fit among both males and females, with classes defined primarily by the nature rather than the degree of anxiety. The presentation of anxiety disorders among individuals and the observation of unique correlates of classes provide evidence for the utility of individual DSM-IV anxiety disorder categories. Findings emphasize the potential value of early interventions and gender-specific conceptualization and treatment of anxiety disorders. (2) We have also assessed the prevalence and correlates of eating disorders in the NCS-A. We found that the lifetime prevalence of anorexia nervosa, bulimia nervosa, and binge eating disorder were respectively 0.3%, 0.9%, and 1.6%. Important differences were observed between anorexia nervosa and other eating disorders concerning sociodemographic correlates, psychiatric comorbidity and suicidality. Although the majority of adolescents with an eating disorder sought some form of treatment, only a minority received treatment specifically for their eating or weight problems. Their severity is demonstrated by generally strong associations with other psychiatric disorders, role impairment, and suicidality, and the unmet treatment needs in the adolescent population place these disorders as important public health concerns. (3) We have examined the 12 month prevalence and comorbidity with other physical conditions in the NCS-A. Migraine status in the past 12 months was assessed using modified International Headache Society (HIS) criteria. Presence of other physical conditions was assessed using a questionnaire addressed to a parent or parent surrogate and reported across the spectrum of headache sufferers. We found that the prevalence of migraine without aura was 8.0% (4.9% in males and 11.3% in females) and migraine with aura was 0.9% (0.8% in males and 0.9% in females). Individuals with any type of headache more frequently reported other neurologic conditions such as epilepsy, persistent nightmares, and motion sickness. Adolescents with migraine were more likely to have a diagnosis of asthma and seasonal allergies compared to those with non-specific headache. Two manuscripts have been drafted and have been submitted for publication. During the next year, we plan to: (1) expand our understanding of mental disorders and service utilization in adolescents by examining risk and protective factors at the level of the individual, family, and community;(2 )investigate the role of immigration and school/neighborhood factors on mental disorders in youth;(3) examine patterns of comorbidity between mental and physical disorders;(4) conduct analyses among subgroups linking data from other national and international studies;and (5) complete the salivary stress hormone assays and evaluate their association with mental disorders in adolescents. Public Health Impact: Aside from providing the first prevalence data on a wide range of psychiatric disorders in a nationally representative sample of U.S. adolescents, the results of this study demonstrate that common mental disorders in adults first emerge in childhood and adolescence. The severity of disorders under study is also demonstrated by the high degree of comorbidity, clinical distress, role impairment, and suicidality among youth with mental disorders. In consideration of the substantial proportion of young people with severe mental disorders that have never received specialty mental health care, the marked racial disparities in lifetime mental health treatment for mood and anxiety disorders, the magnitude unmet needs in mental health treatment are of great importance in public health. Our results further highlight the need for a transition from the common focus on treatment of U.S. youth to that of prevention and early intervention. Future work on this rich resource will help to address the dramatic personal and societal impact of adolescent mental disorders in order to help establish sound public health policy and design health programs and services.